Single-bath chrome dyeing process



Patented Feb. 7, 1950 SINGLE-BATH CHROBIE DYEING PROCESS FOR WOOL Friedrich Felix and Alphonse Heckendorn, Basel, Ernst Reich, Neue Welt, and Fritz es'terlein, Basel, Switzerland, assignors to Ciba Limited, Basel, Switzerland, a Swiss firm N0 Drawing. Application September 20, 1945, Se-

rial No. 617,697. 1944 4 Claims.

The U. S. Patents Nos. 2,170,262, 2,120,741, 2,199,048 and 2,276,187 describe ester-like dyestuff derivatives which are obtainable by the treatment of dyestuffs containing hydroxy groups with organic acylating agents which in addition to the group effecting acylation contain at least one substituent which imparts solubility to the a'cylation product, if necessary after suitable conversion. From these acylation products, the original dyestuflf which is as a rule difiicultly soluble is regenerated by treatment with saponifying agents. If this is done on the fiber, dyeings are obtained which may distinguish themselves by excellent wet fastness properties.

The U. S. Patent No. 2,095,600 further states that the acylation products can be used for dyeing a very wide variety of materials, especially textiles of animal or vegetable origin. Yet the examples show that they are used chiefly to dye textiles which either contain or consist of cellulose, the regeneration of the dyestuff being preferably conducted by saponifying with alkaline saponifying agents. Although the dyeing of wool is described, saponification is nevertheless performed with the aid of alkaline saponifying agents. Since the esterification products are much more readily saponified by alkaline saponifying agents than by acid ones, difiiculties will be experienced when attempting to saponify on the animal fiber with the aid of an acid medium. Thus, for instance, it will not be possible without difiiculty to dye by the usual after-chroming method in satisfactory manner with the use of the azo-dyestuff obtained from diazotized l-hydroxy-2-amino-4-chlorobenzene fl-naphthol and esterified with benzoylchloride monosulfonic acid.

The surprising observation has been made that the esters obtained according to the process of U. S. Patents Nos. 2,170,262, 2,120,741, 2,199,048 and 2,276,187 can successfully be after-chromed on the fiber if dyeing is performed in the presence of alkali chromate and a salt with a buffering effect such as ammonium sulfate. This almost neutral dyeing process, which is known in literature for instance as the metachrome or synchromate process, leads to surprisingly excellent chromlng effects.

The present process is generally applicable and consists in the joint use of agents yielding metal in the single bath dyeing process and of the esters of the type defined above and obtained from azo dyestuffs containing the atomic grouping :cRi-N=N-R2y wherein R1 stands for an aromatic nucleus and In Switzerland October 6,

:c for an atomic grouping standing in ortho-position relatively to the -N=N- group and being capable of taking part in the formation of a complex compound of heavy metals, as, for instance, a carboxyl group or a hydroxyl group, and Rz-g for the radical of a coupling component wherein 1/ stands for a hydroxyl group in ortho-position relatively to the -N=1 lgroup. There may be used as agents yielding metal not only chromium compounds, but copper, nickel, iron, cobalt and other compounds may as well be used. Neither is the process confined to the use of esters of monoazo dyestuffs; esters of polyazo dyestuffs may alternatively'be used, provided they contain at least once the atomic grouping of the above general formula. Such dyestuffs are, for instance, the coupling products from 1 mol of tetrazotlzed 4:4'-diamino-3:3'-dihydroxydiphenyl and 2 mols of Z-hydroxynaphthalene; from 1 mol of diazotized 4'-chloro 4 amino-Z-methyl-S-hydroxy- 1:1'-azobenzene and 1 mol of 2-hydroxynaphthalene or l-hydroxy-l-methylbenzene; from 1 mol of diazotized 1-hydroxy-2-amino-4-chlorobenzene and 1 mol of diazotized 1-amlno--4- chlorobenzene and 1 mol of 1:3-dihydroxybenzene, etc.

To produce the esters from the above mentioned dyestuffs, there may be used, for instance: benzoylchloride sulfonic acid, the dichloride of meta-sulfobenzoic acid, benzoic acid 3:5-disulfochloride, the sulfochloride of salicylic acid, sulfoacetic acid chloride, also 4-chloromethylbenzoyl chloride and other similar esterifying agents which are used advantageously in the presence of tertiary bases, such as pyridine or thiazole.

The new process becomes specially interesting through the use of water-soluble esters of dyestuffs of the type described above and obtained from ortho-hydroxylated or ortho-carboxylated diazo compounds, the practical utilization of which would otherwise be difficult, if not impossible on account of their diflicult solubility or insolubility. It permits thus of the use in the socalled single bath chroming process of dyestuffs, such as unsulfonated azo dyestuffs obtained from diazotized ortho-aminohydroxy compounds or ortho-aminocarboxylic acids and naphthols.

Furthermore, the new process is not applicable solely to animal fibers; it is also successfully used, for instance, in dyeing mixed fabrics made, for instance, from wool and regenerated cellulose.

There may be dyed according to the new process still other types of fibers such as, for instance, natural silk, animalized cellulose, also artificial fibers made from casein or from superpolyamides or superpolyurethanes, etc. The new process is applicable to the various stages of working up such textiles, for instance to loose goods, like loose wool or mixtures of loose wool with loose cellulose wool, also to sliver, worsted yarn, or carded wool yarn on the crosswound bobbin or in the form of skeins and, finally, in the piece.

Due to their excellent solubility the new esterlil-ze dyestuffs are especially suited for machine dyeing and the excellent fastness to fulling of the dyeings is specially valuable for the manufacture of goods from mixed fabrics or woven colored goods.

If the esterified starting materials are dyestuffs obtained from components which impart afdnity for vegetable fibers the process can also be applied to dye cotton or regenerated cellulose. Dyeing may in such case be performed in the presence of agents yielding copper.

The following examples illustrate the invention, but are not to be regarded as limiting it in any way, the parts being by weight:

Example 1 The preparation obtained by the treatment of 29 parts of the dyestufi of the formula COOH (')H obtained from diazotized l-aminobenzene-Z-car- .boxylic acid and 2-hydroxynaphthalene with 22-30 parts of benzoylchloride sulfonic acid is used to dye wool as follows:

100 parts of well wetted wool are introduced at 60 C. into a dyebath containing in 4000 parts of water 2 parts of this preparation, 2.5 parts of ammonium sulfate, 2.5 parts of sodium chromate and parts of Glauber salt, the temperature is raised to the boiling point in the course of minutes and dyeing is carried out for 45 minutes at the boil. 0.5-1 per cent. of acetic acid of per cent. strength is then added and dyeing is continued at the boil for another hour. The wool is then rinsed and dried. It is dyed fast brownred tints.

Wool which is likewise dyed brown-red tints is obtained if instead of the indicated dyestuff, the dyestuff obtained from diazotized 4-chloroaminophenol and 1-hydroxynaphthalene-4-sulfonic acid and esterified with benzoic acid sulfochloride is used.

Example 2 100 parts of well wetted wool are introduced at 60 C. into a. dyebath containing in 4000 parts of water 2 parts of the dyestufi preparation obtained by coupling diazotized l-hydroxy-2-amin0benzene with 1 -(2-chloro) phenyl-3-methyl-5-pyrazolone, corresponding to the formula and esterifying with benzoylchloride-disulfonic acid, 2.5 parts of ammonium sulfate, 2.5 parts of sodium chromate, and 10 parts of Glauber salt, the temperature is raised to the boiling point in the course of 30 minutes and dyeing is carried out for minutes at the boil. 0.5-1 per cent. of acetic acid of 40 percent. strength is then added and dyeing is continued at the boil for another hour. The wool is then rinsed and dried and is dyed fast orange brown tints.

Example 3 The dyestufi from diazotized l-hydroxy-2- aminobenzene and 2 4-dihydroxyquinoline, corresponding to the formula is converted into a water-soluble, ester-like preparation by treatment with benzoylchloridedisulfonic acid. This preparation is used to dye wool as follows:

100 parts of well wetted wool are introduced at C. into a dyebath containing in 2000 parts of water 1 part of this preparation, 2.5 parts of ammonium sulfate, 2.5 parts of sodium chromate and 10 parts of Glauber salt, the temperature is raised to th boiling point in the course of 30 minutes and dyeing is carried out for 45 minutes at the boil. 0.5-1 per cent. of acetic acid of 40 per cent. strength is then added and dyeing is continued at the boil for another hour. The wool is then rinsed and dried and is dyed fast bordeaux tints.

As agent yielding chromium there may be used sodium bichromate instead of sodium chromate if in such case the ammonium sulfate be replaced partly by sodium carbonate or sodium bicarbonate. The corresponding salt of potassium may alternatively be used.

Example 4 parts of well wetted wool are introduced at 60 G. into a dyebath containing in 3000 parts of water 1.5 parts of the dyestuff obtained from l-hydroxy-Z-aminobenzene and acetoacetic acidortho-anisidide, corresponding to the formula /C-CH1 OCH o-HN and esterified with benzoylchloride sulfonic acid,

2.5 parts of ammonium sulfate, 2.5 parts of sodium chlromate, and 10 parts of Glauber salt, the temperature is raised to the boiling point in the course of 30 minutes and dyeing is carried out for 45 minutes at the boil. 0.5-1 per cent. of acetic acid of 40 per cent. strength is then added and dyeing is continued at the boil for another hour. The wool is then rinsed and dried and is dyed fast orange tints.

Example 5 The preparation obtained by treatment of 12 parts of the azo dyestufi from diazotized l-hydroxy-2-amino-4-chlorobenzene and 2-hydroxynaphthalene, corresponding to the formula with 15 parts of benzoic acid-3:5-disulfochloride is used to dye wool as follows:

100 parts of well wetted wool are introduced at 60 C. into a dyebath containing in 4000 parts of water 2 parts of this preparation, 2.5 parts of ammonium sulfate, 2.5 parts of sodium chrmate and parts of Glauber salt, the temperature is raised to the boiling point in the course of 30 minutes and dyeing is carried out for 45 minutes at the boil. 0.5-1 per cent. of acetic acid of 40 per cent. strength is then added and dyeing is continued at the boil for another hour. The wool is then rinsed and dried and is dyed fast red-violet tints.

If instead of the azo dyestuff obtained from diazotized 1-hydroxy-2-amino-4-chlorobenzene and 2-hydroxynaphthalene, the one obtained from diazotized 1-hydroxy-2-amino-4-chlorobenzene and 2:4-dihydroxyquinoline, corresponding to the formula is used and the procedure indicated in this example is followed. the wool is dyed fast bordeaux tints.

The following table shows the pH values existing in the dyebath in each of the foregoing examples:

What we claim is:

1. A process for the production of fast dyeings on wool which comprises performing the dyeing operation with an ester of a monoazo dyestuff of the formula wherein R1 stands for an aromatic nucleus of the benzene series, m stands in ortho-position relatively to the -N:N- group and represents a member of the group consisting of OI-I and -COOI-I, Rz-y stands for the radical of a coupling component, 3 being a hydroxyl group which stands in ortho-position to the N:N- group, at least one of said hydroxyl groups being acylated by a benzoyl radical which contains at least one and at the most two sulfonic acid groups and is free from further substituents, such dyeing being conducted by the single bath process according to which the material to be dyed is treated in a medium having a pH within the range from substantially 6 to substantially 7.35, with a solution containing at the same time dyestuff, an alkali chromate, and ammonium sulfate.

2. A process for the production of fast dyeings on wool which comprises performing the dyeing operation with an ester of a monoazo dyestuff of the formula wherein R1 stands for an aromatic nucleus of the benzene series, Rzy stands for the radical of a coupling component, each 11 standing in orthoposition to the --N:N- group and representing a hydroxyl group, at least one y being acylated by a benzoyl radical which contains at least one and at the most two sulfonic acid groups and is free from further substituents, such dyeing being conducted by the single bath process according to which the material to be dyed is treated in a medium having a pH within the range from substantially 6 to substantially 7.35, with a solution containing at the same time dyestufi, an alkali chromate, and ammonium sulfate.

3. A process for the production of fast dyeings on wool which comprises performing the dyeing operation with an ester of a monoazo dyestuff of the formula wherein R1 stands for an aromatic nucleus of the benzene series, Rz--y stands for the radical of a hydroxy compound of the naphthalene series, each 11 standing in ortho-position to the N:N group and representing a hydroxyl group, at least one y being acylated by a benzoyl radical which contains at least one and at the most two sulfonic acid groups and is free from further substituents, such dyeing being conducted by the single bath process according to which the material to be dyed is treated in a medium having a pH within the range from substantially 6 to substantially 7.35, with a solution containing at the same time dyestuff, an alkali chromate, and ammonium sulfate.

4. A process for the production of fast dyeings on wool which comprises performing the dyeing operation with an ester of a monoazo dyestuff of the formula wherein R1 stands for an aromatic nucleus of the benzene series, R2y stands for the radical of a coupling component which owes its coupling capacity to the presence of an enolizable keto group, each y standing in ortho-position to the N=N-- group and representing a hydroxyl group, at least one 11 being acylated by a benzoyl radical which contains at least one and at the most two sulfonic acid groups and is free from further substituents, such dyeing being conducted by the singl bath process according to which the material to be dyed is treated in a medium having a pH within the range from substantially 6 to substantially 7.35, with a solution containing at the same time dyestuff, an alkali chromate, and ammonium sulfate.

FRIEDRICH FELIX.

ALPI-IONSE HECKENDORN.

ERNST REICH.

FRITZ OESTERLE-IN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,895,019 Barnes Jan. 24. 1933 2,170,262 Graenacher Aug. 22, 1939 2,199,048 Graenacher Apr. 30, 1940 2,237,483 Graenacher Apr. 8, 1941 2.276.187 Graenacher Mar. 10, 1942 Certificate of Correction Patent No. 2,496,386 February 7, 1950 FRIEDRICH FELIX ET AL.

It is hereby eertified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4, line 56, for chlromate read ehromate;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 6th day of June, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

1. A PROCESS FOR THE PRODUCTION OF FAST DYEINGS ON WOOL WHICH COMPRISES PERFORMING THE DYEING OPERATION WITH AN ESTER OF A MONOAZO DYESTUFF OF THE FORMULA 